Cut your two pieces of card to the size you want your photo-frame to be. Check what size the photo you want to put in it is first. You want the pieces of card to be about 6 – 8cm wider and longer than your photo.
Draw a rectangle in the middle of one of the pieces of card using a ruler. The rectangle should be just a bit smaller than your photo.
Cut the rectangle you drew out.
Paint one side of each piece of card if you want to add some colour.
When the paint is dry, stick your shells to the glue and leave it to dry. You might want to stick some sand on the card too.
When the glue is dry, put your photo between the two pieces of cardboard and glue them shut.
When the whole thing is dry, display your shell photo-frame somewhere everybody can see!